TECHNICAL: GENERAL AVIATION
Grob redesigns G115 to meet USAF needs
BY JULIAN MOXON
ilN BRUSSELS
German light aircraft manu facturer Grob has em
barked on a total redesign of the
Gil5 trainer to meet what it
calls "professional military and
civil training requirements".
Production of the original
Gif5, of which i05 have been
sold, has been stopped.
Although Grob had already-
decided on the move, one of the
driving forces behind the deci
sion is the US Air Force's En
hanced Flight Screening (EFS)
programme, in which i20 air
craft are needed for primary
flight training. Grob was to
decide at the beginning of April
whether to compete for EFS, for
which a request for proposals is
due in May.
The company, known princi
pally for its gliders and for the
Egrett high-altitude surveillance
aircraft, will have move ex
tremely quickly to certify the
new aircraft, called the G115T,
if it decides to bid for the
February 1992 EFS contract.
Grob says it is already building
a G115T cockpit mockup and
wind-tunnel testing a new wing
design. "We're hoping to fly it
at the end of this year," says
Grob's Konrad Lewald.
The company says it will con
tinue with the Gil5T pro
gramme even if it does not
compete for EFS. "There's a
very big market out there for
commercial- and military light
trainers," says Lewald. "The av
erage age of trainers in this
category is 23 years."
Two Gii5T models will be
built. The Gii5T/A is a basic,
149kW (200hp), fixed-under
carriage trainer aimed more at
the lower-cost commercial
trainer market, while the ii5T/
B meets the requirement for a
more sophisticated trainer with
retractable undercarriage and a
194kW engine. Unlike the origi
nal Gil5 (the most powerful
version of which had a 134kW
engine), both aircraft are fully
aerobatic with +6/-3g capability.
Principal airframe changes in
clude a strengthed fuselage,
slightly smaller wings with less
aspect ratio, a completely rede
signed cockpit which meets mil
itary specifications and acco
modates 99 per cent of pilot
sizes. The result, says Grob, will
be an aircraft with a 130-i40kt
(240-260km/h)cruising speed,
and a rate of climb at the
maximum F,f50kg take-off
weight of 8.1 m/sec (1,600 ft/
min) against 7.6m/sec for the
most powerful version.
"It is a total redesign," says
Lewald, "and we have already
had a great many enquiries from
potential commercial and mili
tary customers." The Gil5T
will also be offered to private
buyers wanting a "fast, sporty
aircraft...it will be the Porsche
of the air", he adds. The cost of
the G115T will be "between
$187,000 and $215,000". a Grob stops G115 production as redesign gets underway
Terzi test-flies aerobatic T-30 Katana
Terzi Aerodine has test flown its T-30 Katana single-seat
aerobatic aircraft for the first
time, after a number of delays.
The aircraft, which first flew
earlier this year, is being offered
complete or as a kit, with two
engine options also available.
The T-30C is powered by a
225kW (170hp) Textron Ly
coming 10-540 flat-six engine,
fitted with either a Hoffmann or
a Muhlbauer three-blade con
stant-speed wooden propeller.
The T-30E will be powered by
a 300kW Textron Lycoming
T-30 Katana heads for next European
flat-eight engine driving a
Muhlbauer four-blade constant-
speed propeller.
The aircraft is designed by
Pietro Terzi, who has worked
with well-known Italian light
aircraft designer Stelio Frati.
The Italian aircraft has a
short-coupled fuselage design.
One of its characteristic features
is the large wing-fuselage fair
ing, deepest at the trailing-edge
root. This, along with a thick-
section aerofoil and blunt lead
ing edge, is intended to reduce
drag at high lift.
acrobatic championships
v
The aircraft has a welded
chrome-molybdenum steel-tube
fuselage with a carbon compos
ite skin; the wings have a riv
eted aluminium-alloy skin. The
Katana has a maximum man
oeuvring speed of 195kt
(360km/h) and is designed to
cope with +12g to -12g exam
ples. It is scheduled to fly at the
next European acrobatic cham
pionships.
Terzi says that the aircraft's
deveiopment was slowed by the
fact that the company was also
working on the design of the T9
Stiletto light aircraft.
He says that two aircraft are
on order, a T-30C and a T-30E.
The latter is only available in kit
form. Both manoeuvers are ex
pected to be flying by the end
of this year. •
NEWS IN BRIEF
SOVIET AIRSHIPS
The Soviet Union has re
established an airship design
bureau and intends to begin
designing a new airship. The
bureau has been set up at
Dolgoprudny, near Moscow,
with Piotr Dementyev as
chief designer.
18 FLIGHT INTERNATIONAL 10 - 16 April, 1991